Restoration of functional grasping would be of great benefit to people with hemiparesis post stroke. While task-specific training may be the best way to promote functional recovery, implementing such training for grasping is difficult because there are an enormous number of grasping tasks multiplied by an enormous number of contexts in which these tasks need to be performed. The long-term goal of this project is to develop individually-tailored, data-driven solutions to the dilemma of how to practice grasping, i.e. in which contexts and when, in order to improve upper extremity function in people with hemiparesis post stroke. Solutions to this dilemma are strongly needed in the current environment of limited rehabilitation services. We propose that specific movement contexts may improve the control and performance of grasping in people with hemiparesis post stroke. This assertion is motivated by findings in neurologically-intact adults suggesting that movement context is a powerful tool to challenge the central nervous system by eliciting different planning and execution strategies for the same movement. Engagement or focused activation from these areas could provide spatiotemporally-appropriate facilitation to affected hand muscles that improves the ability to grasp in people with stroke. In Specific Aim 1, we will determine if hemiparetic grasping is improved when nested within other movements by testing the following hypotheses: a) hand-shaping during grasping will be improved when a grasp is coupled with a reach, b) force production during grasping will be improved when a grasp is coupled with a lift, c) hand-shaping and force production will be improved when both hands grasp simultaneously, and d) the above effects on grasping will be additive. The effects of the above movement contexts will be evaluated for the two types of grasp that are used for most functional tasks, the palmar grasp and the 3-finger precision grasp. Both kinematic and kinetic data will be collected and analyzed because functional grasping depends on accurate hand shaping and 0 n coordinated force productions. Results from the proposed studies will enable clinicians to implement individually-tailored rehabilitation interventions to improve grasping after stroke. Our results will be particularly salient to clinical practice because they will come from the same time period when the majority of stroke rehabilitation services are provided. Practice of grasping in identified movement contexts during rehabilitation may result in more successful performance, leading to greater recovery of upper extremity function. More successful performance during rehabilitation may also lead to more practice and use outside of rehabilitation.